Exploring montelukast in dogs: A preliminary pharmacokinetic study following oral administration under fasted and fed conditions.

This study investigates the pharmacokinetics (PK) of montelukast (MTK), a cysteinyl leukotriene receptor antagonist increasingly being considered in veterinary medicine. In dogs, MTK has found indications mainly for treating atopic dermatitis as an off-label use. Six male Labrador dogs underwent a single oral administration of MTK (40 mg/dog) in both fasted and fed conditions according to an open, single-dose, two-treatment, two-phase, cross-over design, with a washout period of one week. Blood was withdrawn to heparinized tubes at 0, 0.25, 0.5, 0.75, 1, 1.5, 2, 4, 6, 8, 10, and 24 hr. MTK plasma concentrations were quantified using a validated HPLC method, and the data were analysed using PKanalix™ software with a non-compartmental approach. Concentrations remained quantifiable at 24 hr after administration, under both conditions. No significant differences were observed in the PK parameters between the fasted and fed states. MTK was relatively eliminated slowly, with t1/2 values of 8.10 and 7.68 hr after fasted and fed states, respectively. The attainment of maximum concentration (Cmax) occurred at a Tmax of 4 hr, with mean values of 1.98 µg/mL and 2.80 µg/mL under fasted and fed conditions, respectively. Given the unknown therapeutic range of MTK in dogs and the absence of controlled studies proving its efficacy in this species, further dosing adjustments and refinements should be considered based on both the current PK data and the need to establish an effective therapeutic range, if present. Future research should focus on efficacy studies, multiple-dose investigations, and pharmacodynamic assessments to evaluate the suitability of MTK use in dogs.

Comparative pharmacokinetics of intravenous and subcutaneous pantoprazole in sheep and goats.

Abomasal ulcers are a significant concern in intensive animal farming due to their impact on animal health and productivity. While proton pump inhibitors (PPIs) such as pantoprazole (PTZ) show promise in treating these ulcers, data on PTZ's pharmacokinetics (PK) in adult goats and sheep are limited. This study aims to fill this gap by investigating and comparing PTZ's PK in these species following single intravenous (IV) and subcutaneous (SC) administrations. Five healthy male goats and sheep were included in the study. PTZ concentrations in plasma samples were determined using a validated analytical method. Non-compartmental analysis was conducted, and statistical comparisons were made between IV and SC administrations and between species. Sheep and goats showed similar systemic exposure levels regardless of the administration route. However, sheep had a shorter t1/2 due to a higher Vd compared to goats. Cl values were comparable in both species, with low extraction ratio values. There were no significant differences in Cmax and Tmax between the two species with regards to SC administration, and complete bioavailability was observed. The MAT exceeded the t1/2 in both species, indicating a potential flip-flop phenomenon. Considering the AUC as a predictor for drug efficacy, and observing no significant differences in systemic exposure between sheep and goats for any route of administration, dosage adjustment between the two species may not be necessary. In field settings, SC administration proves more practical, providing not only complete bioavailability but also a longer half-life compared to IV. Further studies are warranted to explore the PK/PD of PTZ in small ruminants with abomasal ulcers, to fully comprehend its therapeutic efficacy in such scenarios.

Comparative disposition kinetics of oral deracoxib in sheep and goats.

This study investigates the pharmacokinetics (PK) of deracoxib (DX), a selective COX-2 inhibitor, in sheep and goats following a single oral dose. DX, approved for dogs, holds potential as an alternative NSAID in small ruminants, particularly in light of heightened concern regarding abomasal ulceration. The study employed an oral administration of DX at a dose of 150 mg/head (sheep and goats), and plasma concentrations were determined after validating a high-performance liquid chromatography method, coupled to a UV detector. The PK parameters, including maximum plasma concentration (Cmax), time to reach Cmax (Tmax), elimination half-life (t1/2), and area under the curve (AUC), were evaluated through non-compartmental analysis. Results showed detectable DX in plasma up to 48 h, with no observed adverse effects. No significant differences in any PK parameters were noted between sheep and goats. Notably, t1/2 values were relatively long, at 16.66 h for sheep and 22.86 h for goats. Despite the fact that both species exhibited comparable drug exposure, high individual variability was noted within each species, suggesting to take into account individual variations in response to DX treatment, rather than species-specific considerations. Additional research involving pharmacodynamics and multiple-dose studies is warranted to comprehensively assess the profile of DX in these species.

Pharmacokinetic evaluation of oral deracoxib in geese (Anser anser domesticus).

The integration of pain management in veterinary practice, driven by heightened animal welfare concerns, extends to avian species where subtle and nonspecific behavioral signs pose challenges. Given that safety concerns with classical NSAIDs highlight the need for more targeted alternatives in birds, this study explores the pharmacokinetic (PK) properties of Deracoxib (DX), a COX-2 selective NSAID approved for use in dogs, following a single oral administration in geese. Six healthy female geese received 4 mg/kg DX. Blood was drawn from the left wing vein to heparinized tubes at 0, 0.25, 0.5, 0.75, 1, 1.5, 2, 4, 6, 8, 10, and 24 h. Plasma DX concentrations were measured using HPLC coupled to an UV detector, and the data were pharmacokinetically analyzed using PKanalix™ software in a non-compartmental approach. The results indicated a terminal half-life of 6.3 h and a Tmax of 1 h, with no observed adverse effects. While refraining from claiming absolute safety based on a single dose, it is worth highlighting that further safety studies for DX in geese are warranted, suggesting a possibility for intermittent use. In addition, drawing conclusions on efficacy and suitability awaits further research, particularly in understanding COX-2 selectivity and protein binding characteristics specific to geese.